NAME

       NetPacket::ICMP - Assemble and disassemble ICMP (Internet Control Message Protocol)
       packets.

VERSION

       version 1.4.4

SYNOPSIS

         use NetPacket::ICMP;

         $icmp_obj = NetPacket::ICMP->decode($raw_pkt);
         $icmp_pkt = NetPacket::ICMP->encode();
         $icmp_data = NetPacket::ICMP::strip($raw_pkt);

DESCRIPTION

       "NetPacket::ICMP" provides a set of routines for assembling and disassembling packets
       using ICMP (Internet Control Message Protocol).

   Methods
       "NetPacket::ICMP->decode([RAW PACKET])"
           Decode the raw packet data given and return an object containing instance data.  This
           method will quite happily decode garbage input.  It is the responsibility of the
           programmer to ensure valid packet data is passed to this method.

       "NetPacket::ICMP->encode()"
           Return an ICMP packet encoded with the instance data specified.

   Functions
       "NetPacket::ICMP::strip([RAW PACKET])"
           Return the encapsulated data (or payload) contained in the ICMP packet.

   Instance data
       The instance data for the "NetPacket::ICMP" object consists of the following fields.

       type
           The ICMP message type of this packet.

       code
           The ICMP message code of this packet.

       cksum
           The checksum for this packet.

       data
           The encapsulated data (payload) for this packet.

   Exports
       default
           none

       exportable
           ICMP message types:
               ICMP_ECHOREPLY ICMP_UNREACH ICMP_SOURCEQUENCH
               ICMP_REDIRECT ICMP_ECHO ICMP_ROUTERADVERT
               ICMP_ROUTERSOLICIT ICMP_TIMXCEED ICMP_PARAMPROB
               ICMP_TSTAMP ICMP_TSTAMPREPLY ICMP_IREQ ICMP_IREQREPLY
               ICMP_MASKREQ ICMP_MASKREPLY

       tags
           The following tags group together related exportable items.

           ":types"
                 ICMP_ECHOREPLY ICMP_UNREACH ICMP_SOURCEQUENCH
                 ICMP_REDIRECT ICMP_ECHO ICMP_ROUTERADVERT
                 ICMP_ROUTERSOLICIT ICMP_TIMXCEED ICMP_PARAMPROB
                 ICMP_TSTAMP ICMP_TSTAMPREPLY ICMP_IREQ
                 ICMP_IREQREPLY ICMP_MASKREQ ICMP_MASKREPLY

           ":strip"
               Import the strip function "icmp_strip".

           ":ALL"
               All the above exportable items.

EXAMPLE

       The following example prints the ICMP type, code, and checksum fields.

         #!/usr/bin/perl -w

         use strict;
         use Net::PcapUtils;
         use NetPacket::Ethernet qw(:strip);
         use NetPacket::IP qw(:strip);
         use NetPacket::ICMP;

         sub process_pkt {
             my ($user, $hdr, $pkt) = @_;

             my $ip_obj = NetPacket::IP->decode(eth_strip($pkt));
             my $icmp_obj = NetPacket::ICMP->decode(ip_strip($ip_obj));

             print("Type: $icmp_obj->{type}\n");
             print("Code: $icmp_obj->{code}\n");
             print("Checksum: $icmp_obj->{cksum}\n\n");
         }

         Net::PcapUtils::loop(\&process_pkt, FILTER => 'icmp');

TODO

       Create constants

COPYRIGHT

       Copyright (c) 2001 Tim Potter and Stephanie Wehner.

       Copyright (c) 1995,1996,1997,1998,1999 ANU and CSIRO on behalf of the participants in the
       CRC for Advanced Computational Systems ('ACSys').

       This module is free software.  You can redistribute it and/or modify it under the terms of
       the Artistic License 2.0.

       This program is distributed in the hope that it will be useful, but without any warranty;
       without even the implied warranty of merchantability or fitness for a particular purpose.

AUTHOR

       Tim Potter <tpot@samba.org>

       Stephanie Wehner <atrak@itsx.com>